자유표면변형을 고려한 저에너지밀도 레이저 용접공정 해석

Abstract

In this study, numerical investigation has been performed on the evolution of weld pool geometry with moving free surface during low-energy density laser welding process. The free surface elevates near the weld pool edge if ∂σ /dT is dominantly negative. On the contrary, the free surface rise at the center of weld pool in case of mainly positive ∂σ /dT . The predicted weld pool width and depth with moving free surface are 5∼15% greater than those with flat weld pool surface. It is considered that weld pool surface oscillation during melting process augments convective heat transfer rate in the weld pool.